The PSG-1 is a semi-automatic sniper rifle based on the H&K G3 battle rifle. It is designed and manufactured by Heckler & Koch of Germany. In the GTA games, the PSG-1 is equipped with both a telescopic sight and a red laser point sight. The rifle has a seven bullet magazine, allowing for (brief) rapid firing, in contrast to the bolt-action mechanism of the regular Sniper Rifle.

The PSG-1 (not an MSG90) in Grand Theft Auto IV is referenced in-game as the Combat Sniper. It has a ten-round magazine, and excellent range. The reticule used is not a standard mil-dot, but the graduated sight found on the Russian SVD Dragunov's PSO-1 scope. During first-person aiming, if the player is standing, there is a noticeable movement of the scope due to Niko Bellic's breathing. This can be minimized by crouching. The Combat Sniper rifle delivers a one-headshot kill in single player and multiplayer, unless the target is armored. It will also kill with about 3 shots to the body. It can easily take down drivers, motorcyclists and, with patience, helicopter pilots.

In every Grand Theft Auto game in which this rifle has been featured in, the player can only fire the rifle in first-person mode. However, in the GTA IV Era, if the player is in cover, the player can fire it in third person mode using the crosshair provided. The rifle can also be blindfired. This is a very useful feature, as it can kill targets at a very far distance while staying safe behind cover and maintaining a clear view of the player's surrounds, therefore spotting potential targets to hide from or eliminate first.

Fort Staunton, Staunton Island - On the balcony of a restaurant. It is easiest to acquire this weapon after the mission "Bringing the House Down" — due to the height of the balcony, it is very difficult to acquire this gun while the restaurant is still intact.

GTA IV

The Combat Sniper can be purchased from the back-alley gun shops for $8,500 and each additional magazine will cost $500. It is also available from Little Jacob, Terry Thorpe in The Lost and Damned, and Armando Torres in The Ballad of Gay Tony for $5,000, with each additional magazine costing $500. It can also be acquired from certain LCPD officers attempting to snipe the player from rooftops in Chinatown and The Exchange.